Actually the operating system of choice for the less-enlightened of the time was CP/M. So SOS looked like CP/M, complete with directory trees, but operated more like DOS 3.3 on the A][. Come on, IBM people, admit it: MS-DOS is really just a souped up version of CP/M, which was out of date by the time the first Apple ][ rolled off the line! --Dave Althoff, Jr. (okay, so I'm a LITTLE biased 8-) )